/*
 * Copyright (c) 2002, 2012, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */

package com.sun.java.swing.plaf.gtk;

import java.awt.Font;
import java.util.*;
import javax.swing.*;
import javax.swing.plaf.synth.*;
import com.sun.java.swing.plaf.gtk.GTKEngine.WidgetType;

/**
 * @author Scott Violet
 */
class GTKStyleFactory extends SynthStyleFactory {

  /**
   * Saves all styles that have been accessed.  In most common cases,
   * the hash key is simply the WidgetType, but in more complex cases
   * it will be a ComplexKey object that contains arguments to help
   * differentiate similar styles.
   */
  private final Map<Object, GTKStyle> stylesCache;

  private Font defaultFont;

  GTKStyleFactory() {
    stylesCache = new HashMap<Object, GTKStyle>();
  }

  /**
   * Returns the <code>GTKStyle</code> to use based on the
   * <code>Region</code> id
   *
   * @param c this parameter isn't used, may be null.
   * @param id of the region to get the style.
   */
  public synchronized SynthStyle getStyle(JComponent c, Region id) {
    WidgetType wt = GTKEngine.getWidgetType(c, id);

    Object key = null;
    if (id == Region.SCROLL_BAR) {
      // The style/insets of a scrollbar can depend on a number of
      // factors (see GTKStyle.getScrollBarInsets()) so use a
      // complex key here.
      if (c != null) {
        JScrollBar sb = (JScrollBar) c;
        boolean sp = (sb.getParent() instanceof JScrollPane);
        boolean horiz = (sb.getOrientation() == JScrollBar.HORIZONTAL);
        boolean ltr = sb.getComponentOrientation().isLeftToRight();
        boolean focusable = sb.isFocusable();
        key = new ComplexKey(wt, sp, horiz, ltr, focusable);
      }
    } else if (id == Region.CHECK_BOX || id == Region.RADIO_BUTTON) {
      // The style/insets of a checkbox or radiobutton can depend
      // on the component orientation, so use a complex key here.
      if (c != null) {
        boolean ltr = c.getComponentOrientation().isLeftToRight();
        key = new ComplexKey(wt, ltr);
      }
    } else if (id == Region.BUTTON) {
      // The style/insets of a button can depend on whether it is
      // default capable or in a toolbar, so use a complex key here.
      if (c != null) {
        JButton btn = (JButton) c;
        boolean toolButton = (btn.getParent() instanceof JToolBar);
        boolean defaultCapable = btn.isDefaultCapable();
        key = new ComplexKey(wt, toolButton, defaultCapable);
      }
    } else if (id == Region.MENU) {
      if (c instanceof JMenu && ((JMenu) c).isTopLevelMenu() &&
          UIManager.getBoolean("Menu.useMenuBarForTopLevelMenus")) {
        wt = WidgetType.MENU_BAR;
      }
    }

    if (key == null) {
      // Otherwise, just use the WidgetType as the key.
      key = wt;
    }

    GTKStyle result = stylesCache.get(key);
    if (result == null) {
      result = new GTKStyle(defaultFont, wt);
      stylesCache.put(key, result);
    }

    return result;
  }

  void initStyles(Font defaultFont) {
    this.defaultFont = defaultFont;
    stylesCache.clear();
  }

  /**
   * Represents a hash key used for fetching GTKStyle objects from the
   * cache.  In most cases only the WidgetType is used for lookup, but
   * in some complex cases, other Object arguments can be specified
   * via a ComplexKey to differentiate the various styles.
   */
  private static class ComplexKey {

    private final WidgetType wt;
    private final Object[] args;

    ComplexKey(WidgetType wt, Object... args) {
      this.wt = wt;
      this.args = args;
    }

    @Override
    public int hashCode() {
      int hash = wt.hashCode();
      if (args != null) {
        for (Object arg : args) {
          hash = hash * 29 + (arg == null ? 0 : arg.hashCode());
        }
      }
      return hash;
    }

    @Override
    public boolean equals(Object o) {
      if (!(o instanceof ComplexKey)) {
        return false;
      }
      ComplexKey that = (ComplexKey) o;
      if (this.wt == that.wt) {
        if (this.args == null && that.args == null) {
          return true;
        }
        if (this.args != null && that.args != null &&
            this.args.length == that.args.length) {
          for (int i = 0; i < this.args.length; i++) {
            Object a1 = this.args[i];
            Object a2 = that.args[i];
            if (!(a1 == null ? a2 == null : a1.equals(a2))) {
              return false;
            }
          }
          return true;
        }
      }
      return false;
    }

    @Override
    public String toString() {
      String str = "ComplexKey[wt=" + wt;
      if (args != null) {
        str += ",args=[";
        for (int i = 0; i < args.length; i++) {
          str += args[i];
          if (i < args.length - 1) {
            str += ",";
          }
        }
        str += "]";
      }
      str += "]";
      return str;
    }
  }
}
